1. Field of the Invention
The present invention generally relates to semiconductor thermoelectric materials and more specifically, to a formation technique which results in the decrease of the thermal conductivity of a semiconductor thermoelectric material.
2. Description of Prior Art
The basic component of the modern thermoelectric device utilizes semiconductors in what is called the Peltier Couple. The Peltier Couple essentially consists of metallic conductors (which ideally exhibit negligible thermoelectric effects) which are coupled through a doped n-type and p-type semiconductor. The nature of the semiconductors allow for a larger energy to be released or required due to changes in transport energy as electrons move between metal to semiconductor and back again. The usefulness of a particular material resides for the most part on three material properties: Seebeck coefficient S, electrical resistivity .rho., and thermal conductivity k.
The usefulness of any thermoelectric material can be described by a figure-of-merit (Z) expressed as: EQU Z=.alpha..sup.2 .sigma./K
where .alpha. is the Seebeck coefficient, .sigma. is the electrical conductivity, and K iS the total thermal conductivity, a sum of lattice and electronic components. No viable device has yet been developed utilizing thermoelectric semiconductor elements since there awaits in the prior art the development of thermoelectric materials with higher figure-of-merits (FOMs) than are presently available.
It is thus desirable from a mathematical analysis to increase the numerator and decrease the denominator of the above equation, thereby increasing Z.
While the prior art has reported using semiconductor thermoelectric materials none have established a basis for a specific material that is dedicated to the task of resolving the particular problem at hand. What is needed in this instance is a formation technique which results in the decrease of the thermal conductivity of a semiconductor thermoelectric material.